Once you have confirmed your switch, you will start receiving a series of emails from GoCompare and their energy switching company Energylinx. This is the company that actually handles the switch on your behalf.
You will also receive a welcome email from your new supplier within a few days. Within 16 days your new supplier will get back in touch and ask you for up-to-date meter readings in order to facilitate your switch. Your current supplier will also use these meter readings to determine your final bill amount.
After approximately 21 days you will be all done and switched to your new supplier. Around this time you should also receive your final bill from your old supplier.